Power-driven rock-drill.



M. KELLOW.

POWER DRIVEN ROCK DRILL.

APPLICATION FILED .IULYH. 1914.

1,281,785. Patented Oct. 15, 1918.

2 SHEETSSHEET 1.

INVENTOR:

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M. KELLOW.

POWER DRIVEN ROCK DRILL.

APPLICATION FILED JULY 1 I. 1914.

' Patented 0011.15, 1918.

2 SHEET$SHEET 2.

Hun em-es PATENT WERE Moses 'KELLOW, on fPENRHYNDEUDRAETH, WALES.

POWER-DRIVEN ROCK-DRILL.

Letters Patent of the United States granted to mean'd dated the 26th May1908. No.

888506 andthe 9th June1908, 'NO. 890,065. The 'presentinvention consistsin certain improve'ments inj-power- 'drills of this class;

" "particularlyin regardto the mode of connecting 'the motor shaft with.the speedreducinggear, in theconstru'ction of the specd-reducinggearwitha view toinsuring its thorough lubrication',and in theconstruction o'fthe' beari'ng between the forward extremity of thespeed-reducinggear and the e'ndfcov'er of the gear-box.

--In the accompanying drawings, Figure 1 is a part longitudinal section.on the line 2"illu'strating the application of my present improvementsto arock-drill of thetype'abovereferred' to. Fig. 2 being atransversesection through the speed-reducing gear taken on the line YYinFig. 1.

The machine viewed as 'a'complete construction consists in aturbine-driven rockdrill wherein the drill rod A and a casing B whereby"it is operated pass through the power-transmitting gear; the latter"being arranged about the part traversed by the section line Y--Y. Thecasing B is in indirect connection through soeed-reducing gear with themotor shaft 0, the latter being rotated by the turbine D. The oppositeextremity of the drill-rod A proiects beyond the left hand end of thecasing B and terminates in a piston (not shown) inclosed in a cylinderE. To the back of which piston water under high pressure is admitted forthe purpose of forcing the drill-rod forward; the latter being capableofsliding longitudinally through the casing B while rotating with andbeing rotated thereby. F is the inlet for high pressure water foroperating the turbine D, and G is the outlet. There being considerabledrag between the drill-rod A and its casing B, a ball-race H is providedbetween a collar B on the casing reducing gear.

Specification of Letters Patent. :Patented Oct, 15, 1918.

Application filedJ'uly 11, 1914. Serial 110,850,455.

B and the end cover J; this ball bearing servingnot only'toresist thelongitudinal thrust ofthe casing B but to center it and its incloseddrill-rod A laterallv. A ballrace is also provided between the turbine.chamber D and the gear-box L for the purpose'of preserving correctalinement and due clearances betweenthe turbine D and other .rotatingparts.

The forward extremity of the turbineshaft C, instead of being externallyscrewthreaded to receive the first pinion of the epicyclicspeed-reducing gear as in my prior construction, is screw-threadedinternally 'and e'ngages alaterally projecting and externally threadedboss or sleeve b -formed on the face of the pinion Z; of the firstspeed- Bythese means, the diameter of the pinion is restricted to aminimuma point of primary importance in gears of the type underconsideration','seeing that the ratio ot'gear train and reduced velocityof the teeth speed-reduction depends on the diameter of the central'pinion in relation to that of the internally toothed circumscribingring.

I have found that in running epicyclic gears, such as employed in myprior con- 'struction, at a very high speed, even in an Oil bath', theintermediate wheels in the highspeed train displace lubricant from thesetscrews or "studs whereon they rotate, owing to the centrifugalaction, and wear badly. To obviate this defect, I employ set-screws orstuds 5 of the maximum diameter prac- "ticable, leaving only sufficientmetal in each applicable to the machine as a whole is more particularlyexplained in my co-pending application Ser. No. 139,911 filed Dec. 30,1916). The set-screws or studs 6 are screwed left-handedly, so thatrotation of the wheels upon them only tends to tighten them againsttheir carrier-plate.

The speed-reducing gear is of the wellknown epicyclic type, and beingrepeated. four times, reduces the speed in four successive stages; FromFig. 2 it will be seen that six intermediate wheels 6 are employed allof which mesh with the central pinion b and with the internally toothedring I)". The central pinion of the second gear train is screwed intothe intermediate wheel-carrier of the first train and so on as regards,the third and fourth trains. The intermediate wheel-carrier of thefourth train is integral with the sleeve B which incloses and actuatesthe drill-rod A. The set screws or studs whereon the intermediate gearwheels are mounted are formed with shoulders which limit-the distancethey can be screwed into the plate and determine the workingclearance'allowed for the intermediate wheels between the carrier plateand the heads of theset screws or studs. As already stated, a holeextends from the central cavity 6 to the external surface of each studor set screw with the effect that the lubricant under the influence ofcentrifugal force, is drawn from the said central cavity and fed to thebearing surface of the stud or set screw whereon the intermediate wheelis mounted. The internally toothed ring forming the outer member of thespeed-reducing gear is held in position by reason of the tightness ofits fit in the gear case or may be secured by means of set-screws.

In practice,1have found that side-thrusts are set up in thedrill-rodwhich tend to cause rapid wear in the bearing at the forwardend of the machine; incorrect aline-.

ment between the drill-rod casing and of the gears resulting, inaddition to which lubricant escapes from the gear-box. Moreover the dragupon the drill-casing, due to the heavy feed-pressure, is considerable;and a great deal of wear takes place between the flange of the ,drillrod-casing and the Phosphor bronze plate in the forward end-cover of themachine.

Copies of this patent may be obtained for In the present construction, aball-bearing H is employed and eliminates any wear in a radial;direction, thus keeping the r0- tating gears in correct position inrelation to the fixed internally-toothed gear. This bearing also takesup the end-thrust and thusperforms a two-fold function; a considerablereduction of friction as compared with my previous construction beforereferred to resulting. In addition to these advantages the rollerbearing permits an effective circulation of oil between the variousrotating parts. To prevent the escape of oil from the gear-boxL thefront end of the drill-casing B is provided with a stuffing-box f and agland 7.

I claim 1. In a turbine-driven rock-drill, wherein the drill-rod and acasing whereby it is 0perated pass through an epicyclicpowertransmission and speed reducing gear, the combination, with ahollow motor-shaft internally'screw-threaded at its forward extremity,of an externally screw-threaded annular projection formedv on the innerpart of the face of the first pinion'of the speed:- reducing gear andadapted to engage in the forward extremity of the said motor-shaft,substantially as set forth.

2. Ina turbine-driven rock-drillfwherein I the drill rod and a casingwhereby it is op. erated pass through epicyclic power-transmission gear,the herein described means for lubricating the planetary wheels,comprising studs with axial and radial holes forming passages andlubricant being fed, under the influence of centrifugal force, throughsaid passages to the internal Working faces of the said planetarywheels.

i M; KELLow.

Witnesses: V

H. D. JAMESON, O. J. WORTH.

five cents each, by addressing the fcommissioner o1 latentsp 7Washington, D. G,

